Upgrades to plate amp for bass modules?

Early B. · « **on:** 6 Oct 2016, 03:10 am »

For those running servo subs --

Has anyone made any upgrades to their A370PEQ plate amps?

gregfisk · « **Reply #1 on:** 6 Oct 2016, 06:42 am »

Quote from: Early B. on 6 Oct 2016, 03:10 am

For those running servo subs --

Has anyone made any upgrades to their A370PEQ plate amps?

I can't imagine you could make them sound better, I have never heard bass like the 12" servo subs from any other speaker. YMMV.

Early B. · « **Reply #2 on:** 6 Oct 2016, 01:09 pm »

Quote from: gregfisk on 6 Oct 2016, 06:42 am

I can't imagine you could make them sound better, I have never heard bass like the 12" servo subs from any other speaker. YMMV.

Well, it's a plate amp, so I'm sure it can benefit from higher quality parts which could result in even better sound.
It would be great if this amp could be placed in a nice chassis to resemble a pair of monoblocks.

mlundy57 · « **Reply #3 on:** 6 Oct 2016, 01:26 pm »

Quote from: Early B. on 6 Oct 2016, 01:09 pm

Well, it's a plate amp, so I'm sure it can benefit from higher quality parts which could result in even better sound.
It would be great if this amp could be placed in a nice chassis to resemble a pair of monoblocks.

You can put it in any type of enclosure you want. If you want an aluminum chasis, anodized or not, check out Landfall Systems https://landfallsystems.com/

Mike

Danny Richie · « **Reply #4 on:** 6 Oct 2016, 03:30 pm »

You might be able to beef up the power supply. Ask Brian Ding about it.

Early B. · « **Reply #5 on:** 6 Oct 2016, 05:37 pm »

Quote from: Danny Richie on 6 Oct 2016, 03:30 pm

You might be able to beef up the power supply. Ask Brian Ding about it.

I asked him a year ago and didn't get a response.

undertow · « **Reply #6 on:** 6 Oct 2016, 05:57 pm »

I have upgraded a few plate amps in the past simply because it was cheap, and they needed work anyway.

Truth is in the "Sub" range basically sound quality comes down to simply current delivery, and more or less
vibration control.

If the space is there you can upgrade your electrolytic power caps with something like 10% bigger uF in capacitance for faster
cleaner current delivery.

and simply replace your woofer output wires with a better wire harness using something like a solid core copper, or silver mix in 12 gauge or
something again for simply lowering resistance as much as possible for current delivery to the woofer.

I have tried other things like removing cheap diodes putting in High speed bridges etc... But its going to have little effect for all the work
on a Sub only amp.

Vibration by damping everything is always better so obviously separate enclosure can help, but I would not get into all of that as even
then your going to get little results unless the system is so refined, and big you want to take into account every little 2% detail.

Folsom · « **Reply #7 on:** 6 Oct 2016, 05:58 pm »

Take some good pictures of them, and I'll try to give you an idea of some possibilities.

undertow · « **Reply #8 on:** 6 Oct 2016, 06:10 pm »

Looks like there are photos right rythmiks site

it looks like you might be able to up the capacitance on the power supply depending on the diameter of the caps and lead spacing, but don't go too big or the in-rush current might start blowing fuses!

Folsom · « **Reply #9 on:** 6 Oct 2016, 06:52 pm »

I have better ideas than that about making it move current better. Frankly changing to bigger caps probably wouldn't do much of anything, but higher quality may be an option depending on sizing. It's a struggle with aftermarket because they tend to go fatter, and the cheaper ones that come on them often go taller, to achieve the size.

If any of you are wanting to have them modded for you, one could be sent to me to take a closer look and establish a price point for modding. The first person to do so will have to evaluate the changes since I don't have a sub setup atm.

Early B. · « **Reply #10 on:** 6 Oct 2016, 07:22 pm »

Great posts, Undertow. I'm at that point of wanting to squeeze out the last 1%, so I'm searching for weak links in my system. The A370 is fairly robust compared to other plate amps, but it's still a plate amp.

There's also some opamps on that board that may benefit from an upgrade. And those sand cast resistors make me cringe.

Early B. · « **Reply #11 on:** 6 Oct 2016, 07:23 pm »

Quote from: Folsom on 6 Oct 2016, 06:52 pm

If any of you are wanting to have them modded for you, one could be sent to me to take a closer look and establish a price point for modding. The first person to do so will have to evaluate the changes since I don't have a sub setup atm.

I'll send you a PM.

undertow · « **Reply #12 on:** 6 Oct 2016, 07:28 pm »

Quote from: Early B. on 6 Oct 2016, 07:22 pm

Great posts, Undertow. I'm at that point of wanting to squeeze out the last 1%, so I'm searching for weak links in my system. The A370 is fairly robust compared to other plate amps, but it's still a plate amp.

There's also some opamps on that board that may benefit from an upgrade. And those sand cast resistors make me cringe.

Yeah honestly OP Amps can benefit to a small degree, but again remember this is a pretty much "Low Frequency" work horse, and honestly there will be very very small benefits vs. something like a DAC, or preamp to go into modding specific circuits with opamps, even bypass caps etc... Mostly in my opinion the most you will push a plate amp is power supply, and like I said possible wiring change to up the overall gauge and quality. Believe it or not I have heard some difference, and definition even on bass drivers doing that.

Power conditioning can help as well, but obviously a high power single outlet conditioner would be best it just depends on how far you want to take it as long as your not fighting ground loops or something in your system already.

Early B. · « **Reply #13 on:** 6 Oct 2016, 07:53 pm »

Quote from: undertow on 6 Oct 2016, 07:28 pm

Yeah honestly OP Amps can benefit to a small degree, but again remember this is a pretty much "Low Frequency" work horse, and honestly there will be very very small benefits vs. something like a DAC, or preamp to go into modding specific circuits with opamps, even bypass caps etc... Mostly in my opinion the most you will push a plate amp is power supply, and like I said possible wiring change to up the overall gauge and quality. Believe it or not I have heard some difference, and definition even on bass drivers doing that.

Keep in mind that subs using these amps are often set to go up to 200 Hz or higher in some cases, so they're doing more than the lowest frequencies.

undertow · « **Reply #14 on:** 6 Oct 2016, 07:58 pm »

Hey if you can get a hold of some good opamps cheap enough, and you can de-solder them cleaning the board out go for it! Can't hurt. Unless these already have Opamp sockets on the board than definitely go for it, but I doubt they do in this case, and dealing with removing them is the bigger problem.

Folsom · « **Reply #15 on:** 6 Oct 2016, 08:12 pm »

Opamps might help. The trick to removal is a razor blade to cut all the legs next to the chip. Then you can flick away the legs, clean pads a little, apply a touch to the first pad, solder in new opamp/socket and then touch the rest of the legs.

You use the razor blade like a saw, gently.

Early B. · « **Reply #16 on:** 29 Oct 2016, 07:06 pm »

UPDATE:

I sent one of my A370 amps to Jeremy (Folsom) so he could evaluate it and make some modification recommendations. Once it arrived, Folsom offered two options that I dubbed, "Level 1" and "Level 2." For now, I opted for the Level 1 mod. Folsom can provide the technical specs on what each level entails.

The amp arrived back home yesterday and I compared it to my stock amp. I used the exact same settings and compared the two amps on the same speaker. My preliminary assessment is that the modded amp definitely sounds cleaner. Actually, the stock amp sounds muddy in comparison, and I never thought I'd ever use the term, "muddy" to describe my servo subs because it's the cleanest bass I ever heard. I had a hunch that the amp could be improved upon, and now I know for sure that there's another level of high fidelity that can be reached by modding the A370.

I would consider this a final mod, after you've exhausted all other significant upgrades, mods and tweaks.

In the next week or so, I'll do some critical listening. My gut tells me that if the bass is cleaner, then the mids and highs, and sound stage may have also gotten a boost.

Here's a before/after pic:

Folsom · « **Reply #17 on:** 30 Oct 2016, 06:28 pm »

Thanks Earl! Just so you guys know there isn't really anything in the way of replacement capacitors. And the upgrade would probably mostly be psychological with them, as real power delivery isn't just about raw farads. The parts I use and how they're used will give you a much more favorable impression of power than just some beefy capacitors.

Yes I guess I have "Level 1" and "Level 2" mods. Level 2 would make the bass deeper and more expansive, feeling more powerful.

Level 1:

Replacement of both diode bridges with discrete, superior, components.
Dampening both secondary windings.
Adding a DENO to ground which reduces common mode noise.
Twisting output and control wires to reduce their field size.

Level 2:

Mounting discrete (superior) diodes off board, with large filters on the DC side.
Dampening both secondary windings.
Adding a DENO to ground which reduces common mode noise.
Twisting output and control wires to reduce their field size.

mikeeastman · « **Reply #18 on:** 30 Oct 2016, 07:13 pm »

how much do you charge for level 2 mods? What is the turn around time?

Folsom · « **Reply #19 on:** 31 Oct 2016, 01:27 am »

Everyone is welcome to PM me, unless Danny doesn't mind me posting prices. (Rules are strictly informative, not advertising, unless given permission or in correct forum circle)

To answer your inquire in time, 2 weeks is pretty standard since some parts come from Canada. Well, that stands for now, I'll be happy to update time frames if I get buried with them.